Layout with Look and Feel - Oracle ADF 11gR2 Development Beginner's Guide - page 206

You can select the style from the list, and a preview of the component style will be displayed in
the right pane with or without themes as shown in the following screenshot:
The Text folder will be helpful in providing visual styles for the text that appears with the
component. For example, the af:inputText component that accepts only numbers can be
displayed visually in a style different from the one that accepts alphanumeric characters. The
+ buton in the skin editor will help you to create addiional style changes to the component.
A user can change the properies of a component using the properies inspector. Any changes
made through the property inspector will be updated in the empSkin.css file. The style class
contains one more folder called Descendant Selectors that will highlight the styles of one
or more components separated by whitespaces. These selectors will allow you to configure the
style of one component when they render within another component.